Face mask seal for use with respirator devices and surgical facemasks, having an anatomically defined geometry conforming to critical fit zones of human facial anatomy, and capable of being actively custom fitted to the user&#39;s face

ABSTRACT

A face seal device for filtering face piece respirators is disclosed. The face seal device is designed to correct inner face seal leakage of particulate material using compensatory accentuations at locations along an inner perimeter based on specific details of a user&#39;s facial human anatomy known to be sites of inner face seal leakage. The face seal may be constructed of a heat activated thermoplastic copolymer that enables the device to be custom fitted to the user&#39;s face.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. application Ser. No.14/447,134, filed Jul. 30, 2014, which, in turn, claims the benefit ofpriority to U.S. Provisional Application No. 61/863,844, filed on Aug.8, 2013 and U.S. Provisional Application No. 61/864,387, filed on Aug.9, 2013, each of which is herein incorporated by reference in itsentirety.

BACKGROUND

1. Field

The present disclosure relates to the design of face seals (FS) forfiltering facemask respirators (FFR), and specifically to minimizing FSinward leakage (FSIL) that occurs in FFRs.

The present disclosure also relates to the use of heat activatedthermoplastic copolymers in the construction of a FS, and to criticalareas of the human facial anatomy as they relate to FSIL.

2. Description of the Related Technology

Filtering face piece respirators (FFRs) play a critical role in everydaylife. They are available for purchase to the general public in mosthardware stores and are recommended, or required, for use in a widevariety of home, public, and occupational environments—especially inhealthcare settings. Their principle function is to provide respiratoryprotection against both non-biological and biological particulatematerials.

In practice, FFRs are used generally to protect the wearer. Inhealthcare institutions, and public health settings, however, FFRs mustfunction both to protect the wearer from potentially harmful particulatematter, including biological pathogens, and/or to protect populationsfrom a wearer exhaling such pathogens into the environment. Duringsurgical procedures, for example, the smoke plume generated fromelectrosurgical use has been shown to contain a wide variety ofvaporized viral organisms capable of infection, including HIV and HumanPapilloma Virus (HPV). A FFR in such a setting must therefore protectthe surgeon and those in the operating room, while at the same timeprotecting the patient from the surgeon's exhaled pathogens coming intocontact with the surgical field. In certain public health settings, FFRsmust be able to effectively protect the wearer and/or the surroundinghuman contacts from biological organisms in a wide range of sizes: fromlarge bacteria at 0.300 to 1.0 micros, to the H7N7 and H7N9 Asian fluvirion, where the particle size can be as small as 40-80 nanometers.

The design features of any FFR that provide its intended protection tothe user are: 1) the filter element itself, and 2) the mechanism ofsealing the mask to the wearer's face.

With respect to the filter materials in the FFR assembly: FFRs arecertified by the National Institutes of Occupational Safety and Health's(NIOSH) approval regulation 42 CFR 84, to provide a variety of levels ofprotection. These NIOSH ratings range from having 95% efficiency atfiltering non-oil based aerosolized particulate matter (N95), to 100%efficiency (P100) in filtering particulate matter that is oil-basedwhere the filter itself must be strongly resistant to oil. Volatileorganic compounds (VOCs) and other such vapor hazards require half faceor full face elastomeric respirators with specific cartridge-basedfilters (OV/P100), which are commonly referred to as “gas masks”.

At the other extreme are simple so-called “dust masks”, and surgicalmasks. It should be noted that surgical masks are not FFRs and are notcertified for use by the NIOSH. Likewise, so-called “N95 surgical maskrespirators”, while being NIOSH certified with respect to the “N95”rating, are not certified by the NIOSH for use in surgery. Instead, asurgical mask of any kind must pass the FDA's approval process whichuses testing standards of the American Society of Testing and Materials(ASTM): F1862, F2100-11, and F2101-07.

For the FFR to provide the stated protection level to the user, it mustpass the Occupational Safety and Health Administration's (OSHA)respirator standard 29 CFR 1910.134, Appendix A, Part 1: “Accepted FitTest Protocols”, Section A: “Fit Testing Procedures—GeneralRequirements”, pp. 1-13, which involves an initial “user seal test” toevaluation the FFR for obvious leaks around the edges of the mask.

A second, more specific fit testing may then be required: OSHA 29 CFR1910.134, Appendix A, Part 1: “Accepted Fit Test Protocols”, Section A:“Fit Testing Procedures—General Requirements”, pp. 14A: “TestExercises”, subsec 1-8 and pp 14B. This is performed with opticalparticle counters, and looks specifically at the actual particleconcentrations outside and inside the mask while it is being worn. Inessence, this is a test of how well the FS on the FFR performs inrelationship to the filter rating of the FFR. This difference, dependingon the experimental design and the filter rating, can represent theFFR's FSIL.

With respect to sealing the mask to the wearer's face, the principalreason to achieve such a seal is to avoid leakage around, rather thanthrough, the filter portion of the mask. This is true for both inhaledand/or exhaled particulate matter coming from the user. There are twocomponents involved: the straps that hold the mask to the face, and theFS itself.

NIOSH certification of FFRs has been a major advance in the developmentand classification of effective filters for FFRs. However there remainsa significant problem with FSIL between the mask and the user's face.FSIL has been shown to occur in virtually all N95 FFRs and is dependenton multiple factors including: overall design of the FFR; FS design andthe material used; the mechanism of attachment of the FFR to thewearer's face; and the particle sizes being filtered. Most reportsconclude that the overwhelming factor in FFR FSIL is the FS componentitself. That is, the filter elements themselves perform very well, ifnot exceeding the NIOSH certification standards. Yet if there is anydegree of FS failure, the protection factor (PF) of the FFR can dropsignificantly: the reduction of protection due to FSIL in some N95 FFRshas been shown to be up to a 90% failure to filter out sub-micron sizeaerosolized particles. This is true for particle sizes less than 0.300μm, which includes many viruses in the size ranges of 40-120 nanometers,in particular the Swine flu and Avian flu viruses.

FSIL creates a unique problem for healthcare workers in operating roomsettings on two fronts:

The first is that a smoke plume is generated during the customarywidespread use of electrocautery during surgical procedures. OSHAestimates that 500,000 workers are exposed to laser and electrocauterysmoke each year. Electrocautery creates particles with the smallest meanaerodynamic size of 0.07 μm—far smaller than the filtering capability ofa N95 FFR. Studies have shown that a range of aerosolized toxins arepresent, including multiple volatile organic compounds that are eitherknown, or suspected, carcinogens. Intact strands of human papillomavirusDNA have been isolated from carbon dioxide laser plumes during treatmentof plantar warts and recurrent respiratory papillomatosis. Viablebacteriophage have also been demonstrated to be present in laser plumes.Whole intact virions have been found and their infectivity demonstrated.HIV DNA has been identified in laser smoke, and has also been shown tobe capable of transmitting infections into cultured cells.

As far back as 1981 there were opinions being stated as to the need fornew standards for protective masks in the operating room environment(see: “Proposed Recommended Practice for OR Wearing Apparel, AORNJOURNAL, v. 33, n. 1, pp. 100-104, 101. 1981”). The AORN has alsopublished a Position Paper on the hazards of surgical smoke for severalyears, calling for “ . . . high filtration surgical masks (to be) wornproperly”.

It is recognized that the inhalation dangers in surgical settings arecompounded by the non-use of N95 respirators in all but those proceduresinvolving HPV containing lesions—such as in the laser removal of genitalwarts. In the vast majority of surgical procedures, during whichextremely high levels of particulate material are generated into thesmoke plume, there is no requirement for N95 FFRs to be worn. Manyinvestigators now agree that the protection provided by surgical masksmay be insufficient in environments containing potentially hazardoussub-micron-sized aerosols.

However, even if N95 FFRs were to be required in operating rooms toprotect the user from the wide range of harmful particles in surgicalsmoke, the FSIL failures of such FFRs will result in significantreductions of the expected protection afforded to the user.

The second problem unique to the operating environment is the sheddingof potentially infectious bacteria onto the surgical field. A vastmajority of surgical masks in use today are of a comparatively loosefitting nature and do not generally have a tightly sealed facial border.Typically such masks are manufactured from a variety of molded layeredfibrous filtration materials designed for one-time disposable usage.U.S. Pat. No. 3,613,678 (Mayhew), U.S. Pat. No. 5,307,796 (Kronzer),U.S. Pat. No. 4,807,619 (Dyrud) and U.S. Pat. No. 4,536,440 (Berg) areall examples of the prior art. These features of surgical masks haveraised concerns about the limitations of surgical masks, dating as farback as 1941, and continuing to the present day as to the effectivenessof such masks in preventing infections in surgical patients. Studieshave confirmed that passage of inspired air around the periphery of twotypes of face masks appears to circumvent the mask's ability to screenairborne contaminants. Similar studies have revealed that Gram-positivestaphylococci bacteria—a highly common cause of surgical site infections(SSI), were frequently isolated from air samples obtained throughout theoperating room, including areas adjacent to the operative field.Nasopharyngeal shedding from persons participating in the operation wasidentified as the source of many of these airborne contaminants. Failureof the traditional surgical mask to prevent microbial shedding is likelyassociated with an increased risk of perioperative contamination. Thesedeficiencies take on considerable importance with respect to the costs,both physical and economic, of surgical site SSIs. A 2009 high profilereport by the CDC's Division of Healthcare Quality Promotion estimatedthat there were 290,485 SSI's per year in US hospitals—16% of allhospital acquired infections, second only to urinary catheter relatedinfections. With an estimated average cost of $17,500 per patient, theseSSI's cost upwards of $22 million dollars per year.

Given the previously discussed FSIL issues with all FFRs, in relation tothe sizes of inhaled pathogens, and the sizes of exhaled pathogens, itis accurate to conclude that even the addition of N95 surgical maskrespirators in the operating room will be unlikely to have a significantimpact on the shedding of potentially harmful organisms from exhalationsvapors of surgical personnel into the surgical field.

There have been many ongoing efforts by those of skill in the art toaddress the well-documented issue of FSIL in FFRs, and in surgicalmasks. The most basic design feature used to achieve some degree of atight fit to the wearer's face has been to design the mask body, both insurgical masks and in FFRs, to be generally cup-shaped, and to have someform of a shaping layer where the inner mask perimeter has some slightcurvature of the region from the nasal bridge itself down on to thesides of the nose. Simple face masks, including surgical face masks, aswell as FFRs have utilized this design concept extensively. U.S. Pat.No. 3,613,678 (Mayhew), U.S. Pat. No. 5,307,796 (Kronzer), U.S. Pat. No.4,807,619 (Dyrud), U.S. Pat. No. 4,536,440 (Berg), U.S. Pat. No.4,873,972 (Magidson), U.S. Pat. No. 4,827,924 A5 (Japuntich), and U.S.Pat. No. 6,923,182 (Angadjivand) are just a few such examples that arewell known to those reasonably skilled in the prior art.

Another very common design, in an effort to improve the FS at the nasalbridge section, is to include a malleable nose clip or bar that issecured on the outer face of the mask body centrally adjacent to itsupper edge to enable the mask to be deformed or shaped in this region inorder to obtain a better fit along what is commonly referred to as the“bridge” of the nose. Such nose bars, or clips, are well known to thosereasonably skilled in the prior art.

A nose clip is described in U.S. Pat. No. 5,558,089 (Castiglione), Pat.App, 2011/0067700 (Spoo) and U.S. Pat. No. 5,307,796 (Kronzer). Theseare just a few such examples of the prior art.

Such nose clips are also commonly associated with a strip of foamaffixed to the length of the clip, typically made from materials ofeither polystyrene, polyester, or neoprene. Examples of such foam stripsare described in U.S. Pat. No. 5,765,556 (Brunson), and U.S. Pat. App.2005/0211251 (Henderson).

Another design feature on FSs of the prior art, to improve the FS fit atthe nasal bridge section, is to add some varying degree of asymmetricoutward extension to make the foam strip wider at the sides of the nasalbridge. One such example is U.S. Pat. No. 8,171,933 (Xue) whichdescribes a preformed nose clip that follows a general curve off thenasal bridge to the sides, exerting a force resiliently inward on eachside of the wearer's nose when the mask is worn. This feature is claimedto eliminate the need for the wearer to individually shape the nose clipto the wearer's face. Another such example is U.S. Pat. 2008/0023006(Kalatoor) which also describes a mask body where at least the firstmajor surface of the nose foam has a predetermined concave curvature,which is claimed to have less opportunity to become pinched orunnecessarily deformed before being placed on wearer's face. Theseexamples differ substantially from the present disclosure in that: thefoam strip in these examples only involves the nasal portion of the FSperimeter; it has no inward convex protrusions to address the rest ofthe entire FS perimeter; and in that it does not involve any specificanatomically defined inner perimeter convex accentuations of the FS thatconform specifically to the critical fit zones (CFZs) of the human faceas described herein, and as will be further described in theillustrations below of the present disclosure.

Another such example is U.S. Pat. App. 2008/0099022 (Gebrewold), whichdescribes a respiratory mask that has a nose foam that has a particularpreconfigured shape for assisting in providing a snug fit over thewearer's nose. The nose foam has a nose-contacting surface that isskewed at first and second angles to a plane that extends to the nosefoam. It is also claimed that the fit may be able to be achieved withoutuse of a nose clip. However, this device differs substantially from thepresent disclosure in that the design feature described does not addressthe entire 360 degrees of the FS perimeter, and in that it does notinvolve any other specific anatomically defined inner perimeter convexaccentuations of the FS that conform specifically to the CFZs of thehuman face as described herein, and as further described in theillustrations below of the present disclosure.

Another design feature to improve the FS fit is to include a vapor sealeither across the top portion of the mask to assist in preventingfogging of the mask, or around the entire perimeter of the mask. U.S.Pat. No. 5,383,438 (Raines) is an example of such a design feature, asis U.S. Pat. No. 5,553,608 (Reese), which describes a stretchablematerial around the mask. Such a feature is well known to thosereasonably skilled in the prior art. These features differ substantiallyfrom the present disclosure in that the FS design in these examples hasno specific anatomically defined inner perimeter convex accentuationsthat conform specifically to the CFZs of the human face as describedherein, and as further described in the illustrations below of thepresent disclosure.

Another design feature of face masks and FFRs of the prior art, in orderto improve the FS fit to the user's face, is to utilize differentmaterials than other such masks of the prior art. One such example isU.S. Pat. App. 2007/0039620 (Sustello), which uses an expandable orcompressible material, such as a viscoelastic foam, or other suchmaterials with similar characteristics, to enhance a seal between themask and a user's face in an area extending over the bridge of the noseand generally under the eyes. However this represents a thin layer ofviscoelastic material across the nasal section only, and is primarilyintended to minimize fogging of a user's glasses or goggles due to warmhumid exhalation vapors that, in fact, escape the FS due to FSIL in thedevice itself. Unlike the present disclosure, the feature described alsodoesn't involve any specific anatomically defined inner perimeter convexaccentuations that conform specifically to the CFZs of the human face asdescribed herein, and as further described in the illustrations below ofthe present disclosure.

Another example is U.S. Pat. App, 2012/0017911 (Choi), which describes amask housing that is made entirely of a closed cell foam layer that hasa plurality of fluid permeable openings located therein. The closed cellfoam shaping layer is claimed to provide a sufficient degree ofpliability at the perimeter, and is also claimed to enable the mask bodyto fit comfortably and snugly on a wearer's face without attachment oruse of an elastomeric face seal, nose foam, or nose clip. However,unlike the present disclosure, this device does not involve any specificanatomically defined inner perimeter convex accentuations of the FS thatconform specifically to the CFZs of the human face as described herein,and as further described in the illustrations below of the presentdisclosure.

Some existing FFRs use some form of an adhesive to attach the face sealdirectly to the user's face. U.S. Pat. No. 6,125,849 (Williams) is onesuch example. Another such example is U.S. Pat. No. 8,381,727 (Matich),which describes a mask with a FS comprised of an endless skin adhesiveseal on the inside of the covering, with multiple such adhesive sealsapplied to each other and the inside of the mask shell perimeter. Theauthors provide examples of fit factors (FFs) determined by scientificmeasuring protocols and methods that are well to known to thosereasonably skilled in the prior art. The results showed overall FFimprovements of 20-80 percent when the seal was applied to industrystandard N95 FFRs, versus the same FFRs with their stock FSs. Someindividual FFs were over 300 in “experienced users”, and as high as1170. However, the use of N95 FFRs for such experimental studies can beconsidered problematic. This is due to the fact that for a given N95FFR, a 5% total IL can be expected. Thus if one is trying to compare twoFSs for only their FSIL component of the total IL on a given N95 FFR,then the IL measured cannot entirely be distinguished as only FSILversus trans-filter leakage through the N95 FFR's filter element.

There have also been concerns about comfort issues with adhesives,applied directly to the face, being removed on a regular basis as wouldbe required in many healthcare settings, particularly in surgicalsettings.

FSIL is difficult to reduce because of the significant variances inhuman facial anatomy. Anthropometric studies have revealed thesubstantial differences in the multiple variables of human facialanatomy. These are notable, perhaps not coincidentally, in the threeareas that are common for FSILs to occur: 1) the nasal bridge and thecheek bone, 2) the cheek bone to the edge of the lower jaw, and 3)around and under the area between the undersurface of the chin backtoward the angle of the jaw. The problem of FSIL may also be compoundedby FFRs being made in fairly generic “small, medium, and large” sizes,and often simply as a “one size fits all” design. Therefore it can beseen that for existing FFRs:

-   -   That FSIL is a major problem that impairs critical protection by        up 90%    -   That FSIL is due almost completely to failure of the FS itself    -   That FSIL occurs in specific areas where a FS contacts the human        face    -   That multiple studies by multiple individuals and institutions        of skill in the art have shown that existing FS designs do not        compensate for all such known anatomic areas that correspond to        such areas of FSIL.

There is therefore a need to redesign FFR FSs to decrease, or eveneliminate FSIL. The present disclosure achieves this, by addressing allof the above factors, and represents an entirely new concept in FSdesign. The present disclosure's design is based on:

-   -   specifically defined CFZs identified in human facial anatomy        that correspond to the known areas of FSIL    -   the specific compensations for these areas in the geometric        design of the FS that correspond to the CFZs involved in FSIL    -   the thermally-activated heat-fitting characteristic of the        material used in the FS, such that the FS can be actively fitted        to the user's face

Testing results at the laboratory level, and confirmed in studies ofboth Simulated Workplace Protective Factor (SWPF) and Work PlaceProtective Factor (WPF) settings, performed with N100 FFRs to eliminatethe filter element itself as a factor in FSIL, have shown that the levelof FSIL reduction provided by this presently disclosed apparatusrepresents a highly significant improvement in FS and FFR technology.The protection factors measured are 60-240 times higher than FFR FSs ofthe prior art, and the geometric means (GMs) of the WPFs were over21,000.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

The present disclosure provides a face seal for use in face masks andfiltering face piece respirators (FFRs) of all types, that is comprisedof: (a) a geometric design based upon specifically defined critical fitzones (CFZs) identified in human facial anatomy that correspond to theknown areas of face seal inward leakage (FSIL) that occur in virtuallyall such face masks and FFRs of the prior art, and which are identifiedat: (i) the area bordered by the Rhinion-Osseocartilaginous Junction(“Nasal Bridge”), along the NasoMaxiliary Ridge/Process, the MaxillaryZygomatic Ridge, and on to the Zygomatic Process forward ridge (“cheekbone”) that comprises CFZ-I; (ii) the area from the Zygomatic Processforward ridge (“cheek bone”), along the Bucchal Wall Soft TissueStructures and on to the Mandibular Ramus, Body, Inferior Rim thatcomprises CFZ-II; and (iii) the area from the Mandibular Ramus, Body,Inferior Rim on one side of the face across to the other side'sMandibular Ramus, Body, Inferior Rim, and the Submental Soft Tissues inthe zone between these areas, that comprises CFZ-III; and (b) an innerperimeter geometric design with specific convex and/or concaveaccentuations that are designed specifically to compensate for thecorresponding specific anatomic features of the human face involved inthe Critical Fit Zones I thru III above; and (c) being composed of athermoplastic copolymer material that can be actively fitted to theuser's face.

The present disclosure differs substantially from those face seals ofthe prior art in that all of the areas of human facial anatomy, and offace seal designs of the prior art that are known to be involved inFSIL, have been addressed individually and specifically with uniquedesign features in both the geometry of, and the material compositionof, the present disclosure.

Testing results, at the laboratory level, and confirmed in studies ofboth Simulated Workplace Protective Factor (SWPF) and Work PlaceProtective Factor (WPF) settings, performed with N100 FFRs to eliminatethe filter element itself as a factor in FSIL, have shown that the levelof FSIL reduction provided by this apparatus represents a highlysignificant improvement over those face seals of the prior art. Theprotection factors measured are 60-240 times higher than FFR face sealsof the prior art.

These and other advantages of the present disclosure are more fullydemonstrated in the illustrations and detailed descriptions. Variousembodiments may take on other modifications and alterations withoutdeparting from the spirit or scope of the disclosure as described in theillustrations above. Accordingly, this disclosure is not to be limitedto the above described illustrations, but rather by the limitations setforth in the following claims and any equivalents thereof provided.

GLOSSARY

The descriptive terminology used herein shall have the meanings as setforth below, unless indicated otherwise:

“accentuation, accentuated, accentuated for” means to have or makeconvex and/or concave changes on the shape of the inner perimeter of theface seal embodiments herein described, to achieve the compensatoryfeatures described above.

“compensate(s) for, compensatory, compensated for” all mean to bedesigned to mirror-image the specific area(s) of the facial anatomy thatcorrespond(s) to, and therefore come in contact with, the describedareas of the face seal embodiments herein described.

“concave” means an inward projection, with respect to the innerperimeter of a face seal, away from the inside center of the face seal.

“convex” means an outward projection of the face seal, with respect tothe inner perimeter of a face seal, toward the inside center of the faceseal.

“corresponding accentuations” means areas along the inner perimeter ofthe face seal embodiments herein described, that mirror-image thespecific areas of the facial anatomy herein described that will come incontact to, and hence fit into, these specific areas along the innerperimeter of the face seal embodiments herein described.

“Critical Fit Zone I”: the area bordered by theRhinion-Osseocartilaginous Junction, or “Nasal Bridge” along theNasoMaxiliary Ridge/Process, the Maxillary Zygomatic Ridge, and on tothe Zygomatic Process (forward ridge “cheek bone”).

“Critical Fit Zone II”: the area starting at the Zygomatic Process,along the Bucchal Wall Soft Tissue Structures and on to the MandibularRamus, Body, Inferior Rim.

“Critical Fit Zone III”: the area starting at the Mandibular Ramus,Body, Inferior Rim, along the area on both sides of the under surface ofthe face, and the Submental Soft Tissues across to the oppositeMandibular Ramus, Body, Inferior Rim.

“Experimental Laboratory”: means a testing setup and method in anartificially controlled environment.

“FF”: means a Fit Factor as determined by experimental protocolsconsistent with those as described in OSHA Respirator Standard, 29 CFR1910.134.

“FFoverall”: means a computation based on FFs during each of 8 fit testexercises consistent with those as described in OSHA Respirator Standard29 CFR 1910.134.

“FFR”: means a filtering facepiece respirator.

“FM”: means face mask.

“Face Mask Perimeter”: means any or all points of contact between anyaspect of a FM, a FFR, a half face mask elastomeric respirator, or afull face mask elastomeric respirator, and the corresponding surfaces ofthe human face.

“FS”: means a seal, or an area intended to function as a seal, on a FM,a FFR, a half face mask elastomeric respirator, or a full face maskelastomeric respirator, that is intended to prevent inhaled and/orexhaled particulate matter, or gaseous vapors, from leaking between theperimeter edges of such masks or respirators, and the correspondingsurfaces of the human face that said perimeter edges come in contactwith, which thereby allows said particulate matter, or gaseous vapors,to bypass the filtering elements of said masks or respirators.

“FSIL”: means leakage of inhaled and/or exhaled particulate matter, orgaseous vapors, from outside of a FM, a FFR, a half face maskelastomeric respirator, or a full face mask elastomeric respirator,being worn by a user, to the inside of the said mask or respirator,between the perimeter edge of such mask or respirator—where saidperimeter edge is intended to function as the FS on said mask orrespirator, and the corresponding surfaces of the human face to whichsaid perimeter edge comes in contact with in any way, resulting in saidparticulate matter, or gaseous vapors, bypassing the said mask orrespirator's filter element.

“GM”: means Geometric Mean.

“GSD”: means Geometric Standard Deviation.

“Heated”: means a version of the FS composed of a material, ormaterials, that is designed to be thermally activated in order to becustom-fitted to the user's face, and is being used in its thermallyactivated state.

“Herein”: means as being referred to anywhere in the text,illustrations, and/or tables of this report in any of its forms now, orin the future.

“IL”: means the total amount of leakage of inhaled and/or exhaledparticulate matter, or gaseous vapors, from outside of a FM, a FFR, ahalf face mask elastomeric respirator, or a full face mask elastomericrespirator, being worn by a user, to the inside of said mask orrespirator, resulting in said particulate matter, or gaseous vapors,bypassing the said mask or respirator's filter elements.

“Not Heated”: means a version of the FS composed of a material, ormaterials, that is designed to be thermally activated in order to becustom-fitted to the user's face, and is being used in its non-thermallyactivated state.

“Prototype”: means any N100 FFR herein described with its stock FSremoved and replaced with embodiments herein described.

“Report”: means the work presented herein and in its entirety.

“Stock”: means the form of the device as it is made commercially, orotherwise, available.

“SWPF”: means Simulated Workplace Protection factor, which has anFFoverall based on studies performed in an environment designed to equalas closely as possible the conditions that would be encountered in thework place setting where the intended use of the FFR would take place.

“WPF”: means Workplace Protective Factor, which has an FFoverall basedon studies performed in the actual environment where the intended use ofthe FFR would take place.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the present disclosure will become more fully apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings. It will be understood these drawings depictonly certain embodiments in accordance with the disclosure and,therefore, are not to be considered limiting of its scope; thedisclosure will be described with additional specificity and detailthrough use of the accompanying drawings. An apparatus, system or methodaccording to some of the described embodiments can have several aspects,no single one of which necessarily is solely responsible for thedesirable attributes of the apparatus, system or method. Afterconsidering this discussion, and particularly after reading the sectionentitled “Detailed Description of Certain Inventive Embodiments” onewill understand how illustrated features serve to explain certainprinciples of the present disclosure.

FIG. 1 demonstrates the herein defined Critical Fit Zones, CFZ-I, CFZ-II& CFZ-III, labeled as 9, 10, 11, and as defined by human facial anatomy8.

FIG. 2 demonstrates the inner aspect of a typical cup shaped FM or FFRshell 12, with inner surfaces that correspond to CFZ areas 9, 10, 11.

FIG. 3 demonstrates a complete free standing form of one embodiment of aFS 13 in straight on view with anatomic areas 9, 10, 11 compensated forby the corresponding convex curved accentuations 14, 15, 16.

FIG. 3A demonstrates a plane of bisection 13 c longitudinally throughthe FS 13

FIG. 3B demonstrates a horizontal cross sectional view of FS 13 at thepoint of the bisection plane 13 c, in line with the same cross sectionalview of a FS 13 d with further accentuations of the perimeter 13 b of FS13 represented by new perimeter 13 e of FS 13 d. Both FS 13 and FS 13 dhave the same three parallel points of transection demonstrated byvertical planes 14 a, 15 a, 16 a at the maximum convex accentuations ofareas 14, 15, 16 and areas 14 b, 15 b, 15 b respectively.

FIG. 4 demonstrates one embodiment of a FS 13 applied to the inside ofthe mask shell 12.

FIG. 5 demonstrates the protocol for heat activation of an embodiment ofa FS 13 attached to N100 FFR mask 17, and subsequent fitting onto theuser's face.

FIG. 6 demonstrates the experimental setup apparatus for initiallaboratory FSIL studies, wherein is shown a stock N100 FFR mask 17 withthe stock FS removed and replaced with the FS 13 attached.

FIG. 7 demonstrates the experimental protocol for SWPF and WPF studies,using mask 17 with FS 13 in place.

FIG. 8 is a graph depicting overall fit factors.

FIG. 9 is a graph depicting the results of SWPF studies.

FIG. 10 is another graph depicting the results of SWPF studies.

FIG. 11 is another graph depicting the results of SWPF studies.

FIG. 12 is a chart depicting the WPF results of SWPF studies.

FIG. 13 is a chart depicting numerical results of SWPF studies.

FIG. 14 is a chart depicting the overall fit factors from SWPF studies.

FIG. 15 is a chart depicting the results of SWPF studies for individualface seal masks.

FIG. 16 is a chart depicting individual mask's GMs and GSDs.

FIG. 17 is a chart depicting results of statistical analysis of SWPFstudy results.

FIG. 18 is a chart depicting particle counts during SWPF studies.

FIG. 19 is a chart depicting protection levels determined during SWPFstudies.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

FIG. 1 illustrates the three Critical Fit Zones (CFZs), of the humanface involved in FSIL and as defined herein by: “CFZ-1” 9 being the areabordered by the Rhinion-Osseocartilaginous Junction, or “Nasal Bridge”1, along the NasoMaxiliary Ridge/Process 2, the Maxillary ZygomaticRidge 3, and on to the Zygomatic Process (forward ridge “cheek bone”) 4;“CFZ-2” 10 being the area from the Zygomatic Process (forward ridge“cheek bone”) 4 along the Bucchal Wall Soft Tissue Structures 5 and onto the Mandibular Ramus, Body, Inferior Rim 6; and; “CFZ-3” 11 being thearea from the Mandibular Ramus, Body, Inferior Rim 6 on one side of theface, and the Submental Soft Tissues 7 in the zone from one portion ofthe inferior rim 6 across to the Mandibular Ramus, Body, Inferior Rim 6on the opposite side of the face. It should be noted that anthropometricstudies of the human facial anatomy have documented in detail theextensive differences in all regions of the face, and in particular thedimensions that are involved in the regions that correspond to the CFZs9, 10, 11 above and sited elsewhere herein. Data from multiple studieshave revealed that for any given face with any given face mask, FSILoccurs at one or more of locations 9, 10, and 11 specifically. Thepresent geometric configuration of one embodiment of a FS 13 representsa departure from those devices of the prior art in having specificsubstantial compensatory convex accentuations of the inner perimeter of13 at points 14, 15, 16 corresponding to CFZs 9, 10, 11 respectively.

FIG. 2 illustrates the view of the inside of a typical face mask 12 ofthe prior art. Each of the CFZs 9, 10, 11 corresponding to anatomiccomponents 1, 2, 3, 4, 5, 6, 7 is illustrated as it relates to thecorresponding regions along the inside perimeter of the mask shell 12.

FIG. 3 illustrates one embodiment of a FS 13. CFZs 9, 10, 11 have eachbeen compensated for by specific and substantial corresponding convexaccentuations 14, 15, 16 along the inner perimeter 13 b of FS 13. Eachaccentuation involves a convex curved reciprocal portion that extendsinto the corresponding CFZ zone 9, 10, 11 of the human face that willcome in contact with the FS 13 upon wearing of the mask 12. The regionof 9 has been shown in anthropometric studies to be the shortestperimeter section of the three CFZ regions 9, 10, 11, and alsopossessing the deepest concavity of CFZs 9, 10, 11. Region 14 of FS 13is correspondingly the shortest, and has the most convex accentuation,of regions 14, 15, 16 of the FS 13. Likewise, CFZs 10 and 11 are knownto be similar in length and depth along the human face, although thereis a slightly greater distance involved in CFZ 11 than in CFZ 10.Therefore the corresponding areas 14, 15, 16 of the FS 13 herein aredesigned to be compensating for these slight differences.

In some embodiments of the FS 13, these areas 14, 15, 16 may be furthermodified to conform to, compensate and reciprocate for, the CFZs 9, 10,11 above. In some embodiments, there may be additional anatomicallydefined corresponding accentuations of the FS 13 at points other than,or in addition to, areas 14, 15, 16.

In some embodiments of the FS 13, the areas 14, 15, 16 may becustom-configured to the user's facial features comprised within CFZs 9,10, 11 by being cut from an image guided, computer generated patternthat is unique to the user's face. In some embodiments, there may beadditional anatomically defined corresponding accentuations of the FS 13at points other than, or in addition to, areas 14, 15, 16 that may becustom-configured to the user's facial features comprised within CFZs 9,10, 11 by being cut from an image guided, computer generated patternthat is unique to the user's face. It should be noted that anymethodology of custom cutting the FS 13 and yielding areas 14, 15, 16corresponding to CFZs 9, 10, 11 can be utilized to yield the FS 13 asdescribed above.

In some embodiments of FS 13 the material used may be thermoplasticcopolymer foam. One such thermoplastic copolymer foam may be ethylenevinyl acetate (EVA). However many such thermoplastic copolymer foams areapplicable and well known to those familiar with the prior state of theart. In some embodiments of FS 13 the material used may be a solidthermoplastic copolymer. One such solid thermoplastic copolymer may beethylene vinyl acetate (EVA). However many such solid thermoplasticcopolymers are applicable and are well known to those familiar with theprior state of the art.

In some embodiments of FS 13 the material used may be heat activatedthermoplastic copolymer foam which can be actively molded to a user'sface. One such heat activated thermoplastic copolymer foam may beethylene vinyl acetate (EVA). However many such heat activatedthermoplastic copolymer foams are applicable and well known to thosefamiliar with the prior state of the art.

In some embodiments of FS 13 the material used may be a solid heatactivated thermoplastic copolymer. One such solid heat activatedthermoplastic copolymer may be ethylene vinyl acetate (EVA). Howevermany such solid heat activated thermoplastic copolymers are applicableand are well known to those familiar with the prior state of the art. Insome embodiments of FS 13 the material used may pressure activated. Insome embodiments of FS 13 the material used may be cold activated. Insome embodiments of FS 13 the material used may be a viscoelasticcopolymer foam. In some embodiments of FS 13 the material used may besolid viscoelastic copolymer. In some embodiments of FS 13, thethickness of the material may be anywhere from 1/16 inch up to ½ inch.It should be noted that any thickness of the FS 13 material can beutilized in so far as it allows for the same, or similar, performancesin the testing results as discussed further herein.

FIG. 3A illustrates a hypothetical longitudinal plane of bisection 13 cthrough FS 13.

FIG. 3B illustrates a horizontal cross sectional view of FS 13 and anexample of a different version of the FS 13 which is herein shown as FS13 d. The cross sectional view of both FS 13 and FS 13 d is at the pointof bisection plane 13 c as illustrated in FIG. 3A above. Both FS 13 andFS 13 d have the same three parallel points of transection demonstratedby vertical planes 14 a, 15 a, 16 a at the maximum convex accentuationsof areas 14, 15, 16 and areas 14 b, 15 b, 15 b respectively. It can beseem that both FS 13 and FS 13 d have identical convex accentuations oftheir respective inner perimeters 13 b and 13 e respectively, atlocations indicated at 14, 15, 16 and 14 b, 15 b, 16 b respectively. Thethickness of inner perimeter 13 b of FS 13 at points 14 c, 15 c, 16 ccan be seen as equal to each other, and equal to the rest of theperimeter 13 b of FS 13. In contrast to FS 13, FS 13 d has in the samethree longitudinal planes of bisection, additional accentuations alongperimeter 13 e of FS 13 d, at points 14 d, 15 d, 16 d that areperpendicular to the areas 14 b, 15 b, 16 b.

In some embodiments of the FS 13 d example herein, the additionalperpendicular accentuations along perimeter 13 e of FS 13 d, at points14 d, 15 d, 16 d may be seen as an increased thickness of the innerperimeter 13 e at these locations versus the thickness of the rest ofthe inner perimeter 13 e of FS 13 d. In some embodiments, exampleversion FS 13 d may be made additionally thicker at areas 14 b, 15 b, 16b, along inner perimeter 13 e, by adding further convex accentuationsthat are perpendicular to the axis of 13 e, which are seen at points 14d, 15 d, 16 d along the inside perimeter 13 e, of FS 13 d.

In some embodiments, areas 14 d, 15 d, 16 d of inner perimeter 13 e maybe thinner than the rest of the perimeter 13 e.

In some embodiments, there can be further individual accentuations ofexample version FS 13 d at any number of perimeter points 14 d, 15 d, 16d that may differ from the corresponding areas 14 c, 15 c, 16 c of theinner perimeter 13 b of FS 13.

Exemplary embodiments FS 13 and version FS 13 d, illustrated in FIG. 3,FIG. 3A and FIG. 3B, are not intended to be the only such possibleexamples. It will be apparent to those skilled in the art that numeroussuch configurations of the inner perimeter 13 b of FS 13 may bedesigned, and thereby that these illustrations may take on othermodifications and alterations without departing from its spirit andscope of the disclosure as described in the illustrations above.Accordingly, these embodiments are not to be limited to the abovedescribed illustrations, but rather by the limitations set forth in theclaims that follow.

FIG. 4 illustrates the FS 13 described in FIG. 3 affixed to mask 12,being a typical cup shaped FFR of the variety that are well known tothose familiar with the present state of the art. In some embodiments ofFS 13, the mask 12 design may be of a rectangular configuration. In someembodiments, the mask 12 design may be of a generalized facial formfitting configuration. It should be noted that the outer perimeter 13 aof FS 13 can be configured to be affixed to the corresponding outerperimeter of any such FFR known to those familiar with the present stateof the art. In some embodiments of the FS 13, the entire FS 13 may beincorporated into the construction of the body of the mask 12. It shouldbe noted that the FS 13 can be configured to be incorporated into eitherthe corresponding outer perimeter of, or the body of, any such FFR knownto those familiar with the present state of the art.

In some embodiments, FS 13 can be affixed to, or incorporated into thedesign of, a mask 12 which may be of a half mask respirator design. Insome embodiments, FS 13 can be affixed to, or incorporated into thedesign of, a mask 12 which may be of a full mask respirator design. Insome embodiments, FS 13 can be affixed to, or incorporated into, anyform of device that is intended to either protect and/or cover part orall of the human face. Such applications for the FS 13 can include facegoggles for skiing, aquatic sports face goggles, motorcycle goggles,aviation face goggles, military respirators, and first responderrespirators. It should be noted that this list is not intended to beall-inclusive.

FIG. 5 illustrates the method used to achieve heat-activation of the FS13 in all studies presented herein. In all studies presented herein,fixation of the FS 13 to N100 mask 17 was done with a heat-resistantsilicon based adhesive (TW Permatex Inc., Solon, Ohio). Twelve hourswere allowed for drying time of FS 13 to mask 17. Just prior to use, astandard heat gun (Ryobo Mod. HG600, One World Technologies, Inc.,Anderson, Ohio) was used at set temperature of 500 F deg. In someembodiments, the temperature of the heat source can be less than about100° F., about 100° F., 200° F., 300° F., 400° F., 500° F., or greater,or any temperature therebetween. The gun was held at a distance of 2 infrom the surface face of FS 13. Using constant motion around the surfaceface of FS 13, the heating was carried out for approximately 2 minutes(FIG. 5a ). In the case of the EVA foam, a distinct transition in thesurface appearance occurred from that of a flat back to having aglossier black characteristic. In some embodiments, the distance of theheat source from the surface of FS 13 can be less than about 1 inch, 1inch, 2 inches, 3 inches, 4 inches, 5 inches, 6 inches, 1 foot, 2 feet,or more, or any distance therebetween. The time for applying the heatmay be less than about 30 seconds, about 1 minute, 1.5 minutes, 2minutes, 3 minutes, 4 minutes, 5 minutes, or more, or any timetherebetween. In some embodiments, the FS 13 can be heated to less thanabout 50° F., 60° F., 70° F., 80° F., 90° F., 100° F., 110° F., 120° F.,or more, or any temperature therebetween.

The mask 17 with FS 13 was then positioned on the user's face, by theuser, and the holding straps were adjusted to obtain a secure fit, incompliance with OSHA's to 29CFR1910.134: Part I. OSHA-Accepted Fit TestProtocols; Appendix A, pp. 1-13. (FIG. 5b ). After 90 seconds of coolingtime, testing was begun.

FIG. 6 illustrates the laboratory test environment used, which has beenwidely described for research in the present state of the art (Balazy etal. 2006, Lee, et al, 2004, Choe et al 2000, Grinshpun et al. 2004, Leeet al 2008). A walk-in indoor test chamber (860 ft3=24.3 m3) wasutilized to conduct the initial study. The test chamber was maintainedat a positive pressure of 1 in. w.g. (249 Pa) during the experiments.Sodium chloride solution (NaCl, 1%, w/v) was aerosolized in the chamberby a six-hole collision nebulizer (BGI Inc., Waltham, Mass., USA) at apressure of 20 psi (1.38×10⁵ Pa) and a flow rate of 12 l/min. Dry airwas mixed with NaCl aerosols at a flow rate of 40 l/min. NaCl was usedas a primary test aerosol at concentrations ranging from 4.2×107 to1.9×108 particles/m3. Since laboratory-generated particles may carryhigh electrical charges, the entire airflow of 52 l/min was directedthrough a 10 mCi 85Kr charge equilibrator (Model 3054, TSI, Inc.,Minneapolis, Minn.,) to achieve the Boltzmann charge equilibrium. An aircirculation fan (with a flow rate of 900 CFM) located at the outlet ofthe aerosol generation system distributed the aerosolized particleswithin the chamber.

In the initial experimental study, two different N100 FFR masks 17 wereused, from two manufacturers that are both well recognized by thoseskilled in the art. Each FFR mask was tested in triplicate, in threeversions: the first with the mask 17 stock FS in place; the second withthe mask 17 FS removed and replaced with the FS 13 with a ¼ inchthickness affixed to the inside periphery of 17; the third with thestock FS of 17 removed and replaced with a FS 13 in a ⅜ inch thicknessaffixed to the inside periphery of mask 17. The exhalation valves on themasks 17 were left undisturbed.

In each of the modified prototypes tested, the FS 13 was heat-activatedaccording the protocol as set forth above in FIG. 5.

Initially, the subject performed a user seal check as described in OSHA29CFR1910. Part 1, Appendix A, Sec A, pp. 1-13. All subsequentexperimental studies herein followed the above OSHA protocol, and all ofthe masks—controls and prototypes—passed the user seal check by allsubjects.

A single human subject then performed the quantitative fit testing,which was conducted with a TSI P-TRAK (TSI, Inc., St. Paul, Minn., USA)optical particle counter (OPC), with customized software in order toobtain fit factors >200. Samples were obtained outside the mask (ambientair) and inside the mask via customized fittings placed centrally on themask to which tubing connected the samples to separate OPC's.

Fit-testing exercises were performed according to the OSHA29CFR1910.134, Part 1; Appendix A, Sec 14a “Test exercises”, pp. 1-8.These exercises include normal breathing, deep breathing, turning thehead from side to side, moving the head up and down, talking, grimacemaneuver, bending over and touching the toes, and returning to normalbreathing (US Department of Labor, 1998). Each exercise was performedfor 2 min (versus OSHA's 1-min protocol) and the particle concentrationsinside and outside the respirator were averaged over 1-min periods. Thechallenge NaCl aerosol concentrations were measured inside the Mask 17and outside Mask 17.

The concentration inside the respirator (c-in) for the entire test wasaveraged over all the exercises, excluding the grimace maneuver. Theparticle concentrations outside the respirator (c-out) were measured atthe beginning, middle and end of the test. The average of theseconcentrations was used as the concentration outside the respirator foreach test. The FF was calculated by dividing the particle concentrationsoutside the respirator (c-out) by those inside the respirator (c-in):FF=c-out/c-in.

The particle losses in the sampling line have been addressed in previousstudies (Lee et al., 2004). Therefore, all PFs presented in herein werecorrected by a ratio of concentrations measured in the two samplinglines when no respirator was attached in the system. These ratios variedfrom 0.93 to 1, depending on the particle size.

The data analysis was performed using an analysis of variance (ANOVA)model provided by the Statistical Analysis System version 8.0 (SASInstitute Inc., Cary, N.C., USA). P-values of 0.05 were consideredsignificant. The difference in mean FFs among nine surgical masks wasexamined by the ANOVA followed by a pairwise comparison using theTukey's studentized range test. This statistical method was also used toexamine the difference in the PFs among different particle sizes.

In all studies presented herein the FS 13 was composed of EVA foam(McMaster-Carr, Robbinsville, N.J.).

Study Results are presented herein:

Example 1

FIG. 8 represents results of the laboratory studies performed with thesetup shown in FIG. 6, wherein: “Control-A”=Model A N100FFR mask withthe stock FS; “[A+Proto¼FS]13”=Model A N100FFR mask modified with FS 13having a ¼ in thickness; and “[A+Proto ⅜ FS] 13”=Model A N100FFR maskmodified with FS 13 having a ⅜ in thickness. The same labeling indexapplies to Control Model B N100FFR and all prototype versions of mask 17thereof, and as described herein.

To make each prototype FFR, the Control FFR 17 stock FS was removed andthe FS 13 was affixed to the inner periphery of mask 17 according to theprotocol described in FIG. 5.

Among the two tested control N100 FFR respirators, Control-B performedbetter than the Control-A. In all three single fit tests, the overallfit factor (FFoverall) of the Control-A was below 100; for theControl-B, the FFoverall exhibited geometric mean (GM) slightly higherthan the targeted OSHA threshold of 100. However, the difference betweenFFoverall-values of Control-A and Control-B showed a borderlinestatistical significance (p=0.06).

The [A+Proto¼FS]13 showed significant enhancement as compared to theControl-A with its stock FS: FFoverall GMs were 685 and 34,respectively; p=0.02. It should be acknowledged that the filter of anyN100 respirator is expected to have a filtration efficiency of at least99.97%, which could allow no more than 0.03% of particles to penetrate(one out of ˜3,300), which translates to FFoverall >3,300. This meansthat, if such a respirator features FFoverall in excess of 3,300, theparticle penetration may be attributed solely to the filter material,and not to FSIL; i.e., the respirator could be considered (in a firstapproximation) as “perfectly fit” (no room for the faceseal leakage).Given the difference between 685 and 3,300, [A+Proto¼FS]13 seems to havesome degree of FSIL, although the modification with FS 13 improved thefit over the Control-A respirator by about 20-fold.

The [A+Proto⅜FS]13 showed an improved overall FF: over 100-fold greaterthan the non-modified Control-A and 6-fold greater than the previouslytested [A+Proto¼FS]13. The level is not as high as [B+Proto⅜FS]13 (seebelow), but it's greater than 3,300 (min FF for the N100 filter), whichsuggests either no FSIL, or extremely small FSIL (with the leakpenetration lower than or comparable to the filter penetration).

The [B+Proto¼FS]13 results were as follows: FFoverall showed both[B+Proto¼FS]13 and [B+Proto⅜FS]13 had considerable enhancement ascompared to the Control-B: FFoverall GM-value that was 105 for controlincreased to 1,043 for [B+Proto¼FS]13 (significant difference: p=0.02)and to 25,808 for [B+Proto⅜FS]13 (significant difference: p<0.001). Theoverall fit factor of [B+Proto⅜FS] 13 was 25-fold greater than the onefor [B+Proto¼FS]13. The findings suggest that [B+Proto¼FS]13 still hadat least some degree of FSIL (although much smaller than the Control-B)while [B+Proto⅜FS]13 seems “perfectly fit” (25,808>>3,300, i.e. nomeasurable faceseal leakage.

These results clearly prove that the FS 13, when affixed to both N100FFR 17s Control-A and Control-B, resulted in highly significantlyimproved FFs for both of these FFRs. The results also indicated thatboth [B+Proto⅜FS]13 and [B+Proto¼F S]13 were much better than thecorresponding versions of Control-A. For this reason, all subsequentstudies presented herein utilized the Model-B N100 FFR since this model,in being able to demonstrate essentially no face seal leakage with FS13, would provide the most accurate measurements of FS 13 performance inthe SWPF and WPF studies as reported below.

FIG. 7 illustrates the setup for the Simulated Workplace ProtectiveFactor (SWPF) study performed in a teaching university hospital surgicallaboratory setting. The electrocautery smoke plume measurements weretaken during an ongoing trauma surgery teaching exercise, beingperformed in a swine model, for the surgical residents in training. Thetraining surgery exercise was approved by the institution'sInvestigational Review Board (IRB). The reason this is reported as aSWPF rather than a true Workplace Protective Factor (WPF) study designis solely because in this study setup, and unlike a true hospitaloperating room, there was no temperature and humidity control, and nonegative air flow system. The rest of the study design would equate withthat of a WPF study.

The study surgeon (an experienced board certified general surgeon)positioned himself at a customary distance from the surgical site. Theelectrosurgical generator unit (Valleylab Force FX, Covidien, Boulder,Colo.) was set at a blend current of 40 wts. A standard electrosurgicalpencil (Valleylab E2516, Covidien, Boulder, Colo.) was used. Thesurgical smoke plume was suctioned at a customary distance by anexperienced surgical assistant.

OPC placement, and tubing fixation to each mask tested, was identical tothe protocol as shown in FIG. 6. The OPC measuring the ambient air wasmodified to be able to function with what proved to be extremely highparticle counts in the surgical smoke plume. A 1/10 dilution was usedwhen the ambient concentration was expected to be greater than 500,000particles per cm3, which is the upper threshold of the P-TRAK.

The mask 17 used was identical to the Model-B N100 FFR as detailed inFIG. 6 above. The FS 13 was of the ⅜ in thickness for this study, andfor all remaining study examples reported herein. Each version of themask 17 was tested in triplicate: mask 17 with its stock FS; mask 17with the stock FS removed and replaced with the FS 13 and not heated;mask 17 with the stock FS removed and replaced with the FS 13 and heatedprior to use. Fixation of the FS 13 to the mask 17 was by the processdetailed in FIG. 5. Heat activation of FS 13 was performed as detailedin FIG. 5, with the exception that the mask was held in place on theuser's face, by the user, and the retaining straps placed and securedafter, rather than before, the 90 second cooling period.

It should be noted: in this example and all subsequent study examplesreported herein that:

-   -   the Model-B N100 FFR mask 17 was used, and in its unmodified        state is herein referred to as “Control-B”    -   the FS 13 used was of the ⅜ in thickness version for this study,        and for all of the remaining study examples presented, and is        herein referred to as the “Prototype”    -   the Prototype with the FS 13 having been heated and fitted to        user's face as described in FIG. 5 is herein referred to as the        “HEATED Prototype”    -   the Prototype with the FS 13 in the non-heated version is        referred to herein as the “NON-HEATED Prototype”

Study Results are presented herein:

Example 2

FIGS. 9-11 are results of the SWPF studies done as described in FIG. 7,and represent examples of the time series for the aerosol concentrationsoutside the respirator (ambient) and inside the respirator (mask)measured with a OPC in the operating room with the three study mask 17versions: the Control-B; the NON-HEATED Prototype; the HEATED Prototype

FIG. 12 represents SWPFs determined based on the OPC measurements in theoperating room for the three mask 17 versions (the data from 12 testswere summarized). The bars represent GMs; the error bars representstandard deviations.

FIG. 13 represents numerical data for the SWPF values calculated usingthe time-weighted average concentration values for respirators 1, 4, 7,10 (Control-B); 2, 8, 11 (NON-HEATED Prototype); and 3, 6, 9, 12, 13(HEATED Prototype). The GMs and geometric standard deviations (GSD) areused in FIG. 12 above.

The SWPF of the NON-HEATED Prototypes was 61-fold higher than that forControl-B. This difference between GMs is statistically significant(p=0.0081). Four Control-B FFRs produced different SWPFs with 3 out of 4above 100 and the GM-value close to 100. All three SWPFs produced by theNON-HEATED Prototypes were above 3,300 (the N100 filter can allow topenetrate 0.03% of particles which translates to (SWPF filter)min˜3,300; thus, any value in excess of 3,300 can technically representa “perfectly fit” mask, i.e., the mask for which no measurable facesealleakage was identified.

For the HEATED Prototypes, the SWPF was significantly higher than forthe Control-B (p=0.0032), although it was not as high as for theNON-HEATED Prototypes (contrary to the expectations). The differencebetween the NON-HEATED Prototypes and the HEATED Prototype data sets wasstatistically significant (p=0.0118). The somewhat lower-than-expectedperformance of the HEATED Prototype was attributed to the leakagecreated due to the respirator re-donning (the following sequence wasapplied: heating, donning, taking off, re-donning). This part of theprotocol deviated from the previous fit testing protocol as detailed inFIG. 5, and as used in FIG. 6, Example 1. It is believed that re-donningafter, rather than before, the ninety (90) second cooling perioddescribed in FIG. 5 may not have allowed the user to achieve the sametight fit that was reached on the first donning with the respiratorplaced on the face immediately after heating as described in FIG. 5. Itmay be that certain deformations of the material aimed at mimicking thewearer's facial features may partially solidify between donnings, as therespirator cannot be positioned exactly the same, and FSIL leaks can becreated near these deformations.

A measurable result of using the FS 13 as described herein, in both theNON-HEATED Prototypes and the HEATED Prototypes, is a more consistentperformance: GSDs of both prototypes appeared considerably lower thanthe GSD for controls, as seen from FIG. 13. This result is significantin that the ambient concentration varied sizably (by two orders ofmagnitude in some tests).

Example 3

FIG. 14 represents an experimental study design with the same setup asseen in FIG. 6. and as reported in Example-1. The human subject was thesame as that in Example-2 above, and hence different from Example-1. Thesame heating protocol for FS 13 as in Example-1 was utilized, asdescribed in FIG. 5: after heating, the mask was placed to the face andstraps secured, followed by the 90 second cooling period.

FIG. 15 represents the individual FFs for each mask as indicated in theFigure. Although the fit testing produced lower overall FFs than thoseobtained with the subject in Example-1, the protection levels obtainedwith the FS 13 prototypes were still very high. Both NON-HEATEDPrototypes and HEATED Prototypes produced a FFoverall of approx. 3,700,which is (a) almost two order of magnitudes greater than the Control-Bmask (GM=59), (b) above 3,300 that is assumed to be the filter-yieldedthreshold (which translates into “no measurable faceseal leakdetected”). One of the HEATED Prototypes produced a FFoverall in excessof 10,000, which represents an absolute true “perfect fit”.

The GM FFoverall of the HEATED and NON-HEATED Prototypes in this studyare nearly identical, although the highest FFoverall was with the HEATEDPrototype. The same subject in Example-2, with the same Control-B maskand the same Prototype Masks with FSs 13 had a greater difference in theGM FFoverall between the NON-HEATED Prototypes (higher) and the HEATEDPrototypes (lower). The subject in Example-1, however, had significantlyhigher GM FFoveralls for the HEATED Prototypes than for the NON-HEATEDPrototypes. These findings suggest that: a) the FS 13 functions bestwhen heated and fitted as described in FIG. 5, and b) the HEATED andNON-HEATED Prototypes both substantially outperform the Control-B maskwith its stock FS.

Example 4

This study setup was essentially the same as seen in Example 2, withthree exceptions: 1) a section of animal tissue was used rather than alive animal; 2) the study took place in a fully functional hospitaloperating room with temperature and humidity controls as well asstandard negative air flow; 3) three human study participants were used:the two participants involved in Example 1 and Example 2 & 3, and athird study participant. It should be noted that the anthropometrics ofeach participant's facial anatomy was significantly different, and thatthe first two participants were male and the third participant wasfemale. Thus this study represented a true WPF design.

The OPC measuring the ambient air was modified to be able function withwhat proved to be extremely high particle counts in the surgical smokeplume. A 1/10 dilution was used when the ambient concentration wasexpected to be greater than 500,000 particles per cm3, which is theupper threshold of the P-TRAK.

A total of twenty seven tests were conducted: three with the Control-B,three with the NON-HEATED Prototype, and three with the HEATEDPrototype. The heating protocol was used as described in FIG. 5, and asused in Examples 1 & 3 above. There were three subjects, three replicatetests per subject, and a randomized design was applied. For each test, arepresentative time segment was determined to compare the ambient andin-mask time-averaged aerosol concentrations taken from the time series(in most cases, a continuous monitoring period exceeded 1 min).

FIG. 16 represents individual mask's GMs and GSDs for each mask versiontested.

FIG. 17 represents statistical analysis p-values for the Control-B masksas compared to the NON-HEATED and HEATED Prototypes.

FIG. 18 represents an example of the particle counts during the minutetesting of a NON-HEATED Prototype mask, comparing ambient air countsversus inside mask counts.

FIG. 19 represents a graphical presentation of the protection leveldetermined for the three respirator masks 17 versions—Control-B,NON-HEATED Prototype, and HEATED Prototype—as worn by the three subjectswith three replicate tests per subject.

The findings indicate that no significant between-subject variabilitywas observed in the performance of the Control-B mask and the NON-HEATEDPrototype; the HEATED Prototype exhibited somewhat higher WPFs whentested on subjects SG and VA as compared to subject RK. The Control-Bmask showed a proper fit only 5 times out of 9 (with WPF>100); itexhibited the WPF values ranging from 11.5 to 1,442 with GM of 145.6 anda GSD of 2.1.

The NON-HEATED Prototypes fitted all 9 times out of 9 (with WPF>>100);they exhibited WPF values ranging from 6,494 to 67,185 with a GM of21,262 and a GSD of 1.5 (narrower, i.e. more consistent than the controlmodel).

The HEATED Prototypes fitted all 9 times out of 9 (with WPF>>100); theyexhibited WPF values ranging from 4,584 to 112,502 with a geometric meanGM of 24,923 and a GSD of 1.6.

The difference between WPFs of the Control-B Mask and either of thePrototypes (NON-HEATED or HEATED) is statistically significant (thestrong significance is supported by p<0.01).

The GM of WPFs of the HEATED Prototype is about 15% greater than that ofthe NON-HEATED Prototype; however, this difference is not statisticallysignificant (p>0.05). Thus, the two types of the FS 13 prototype FFRsexhibited similar performance characteristics (both demonstrated muchsuperior protection levels than the Control B N100 Mask FFR.

While this invention has been described in connection with what arepresently considered to be practical exemplary embodiments, it will beappreciated by those skilled in the art that various modifications andchanges may be made without departing from the scope of the presentdisclosure. It will also be appreciated by those of skill in the artthat parts included in one embodiment are interchangeable with otherembodiments; one or more parts from a depicted embodiment can beincluded with other depicted embodiments in any combination. Forexample, any of the various components described herein and/or depictedin the Figures may be combined, interchanged or excluded from otherembodiments. With respect to the use of substantially any plural and/orsingular terms herein, those having skill in the art can translate fromthe plural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations may be expressly set forth herein for sakeof clarity. Thus, while the present disclosure has described certainexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed embodiments, but, on the contrary, is intendedto cover various modifications and equivalent arrangements includedwithin the spirit and scope of the appended claims.

What is claimed is:
 1. A face mask seal, comprising: a first substantially planar surface; a second surface positioned opposite the first substantially planar surface; an outer perimeter, the second surface or outer perimeter positioned for coupling to a face mask; an opening penetrating from the first substantially planar surface to the second surface; and an inner perimeter completely surrounding the opening, the inner perimeter consisting of five convex accentuations and five concave accentuations completely surrounding the opening: two first convex accentuations of the five convex accentuations separated from each other by a first concave accentuation of the five concave accentuations, two second convex accentuations of the five convex accentuations separated from the first two convex accentuations by two second concave accentuations of the five concave accentuations, and a third convex accentuation of the five convex accentuations separated from the two second convex accentuations by two third concave accentuations of the five concave accentuations, the first two convex accentuations heat-moldable for custom conforming to two first critical fit zones, respectively, on a user's face, the second two convex accentuations heat-moldable for custom conforming to two second critical fit zones, respectively, on the user's face, the third convex accentuation heat-moldable for custom conforming to a third critical fit zone on the user's face, the first two convex accentuations, the second two Convex accentuations, and the third convex accentuation retaining their shapes when removed from the user's face, the two first critical fit zones each including nasal bridge, nasomaxiliary ridge, maxillary zygomatic ridge, and a first portion of zygomatic process, the two second critical fit zones each including a second portion of the zygomatic process, bucchal wall soft tissues and a first portion of mandibular ramus, and the third critical fit zone including a second portion of the mandibular ramus on either side of submental soft tissues.
 2. The face mask seal of claim 1 wherein the seal is constructed of a material which is a thermoplastic copolymer, an elastomeric copolymer, or a thermoplastic elastomeric copolymer.
 3. The face mask seal of claim 1, wherein the seal comprises ethylene vinyl acetate (EVA).
 4. The face mask seal of claim 1, wherein the face mask seal is reusable.
 5. A system, comprising a respirator mask and a face mask seal, the face mask seal comprising: a first substantially planar surface; a second surface positioned opposite the first substantially planar surface; an outer perimeter, the second surface or outer perimeter positioned for coupling to a face mask; an opening penetrating from the first substantially planar surface to the second surface; and an inner perimeter completely surrounding the opening, the inner perimeter having consisting of five convex accentuations and five concave accentuations completely surrounding the opening: two first convex accentuations of the five convex accentuations separated from each other by a first concave accentuation of the five concave accentuations, two second convex accentuations of the five convex accentuations separated from the first two convex accentuations by two second concave accentuations of the five concave accentuations, and a third convex accentuation of the five convex accentuations separated from the two second convex accentuations by two third concave accentuations of the five concave accentuations, the first two convex accentuations heat-moldable for custom conforming to two first critical fit zones, respectively, on a user's face, the second two convex accentuations heat-moldable for custom conforming to two second critical fit zones, respectively, on the user's face, the third convex accentuation heat-moldable for custom conforming to a third critical fit zone on the user's face, the first two convex accentuations, the second two convex accentuations, and the third convex accentuation retaining their shapes when removed from the user's face, the two first critical fit zones each including nasal bridge, nasomaxiliary ridge, maxillary zygomatic ridge, and a first portion of zygomatic process, the two second critical fit zones each including a second portion of the zygomatic process, bucchal wall soft tissues and a first portion of mandibular ramus, and the third critical fit zone including a second portion of the mandibular ramus on either side of submental soft tissues; the system further comprising a substantially airtight seal between the respirator mask and the outer perimeter of the face mask seal. 